Hot-gas piston engine comprising one or more closed cycles



Aug. 1951 A. HOROWITZ ET AL 2,564,363

HOT-GAS PISTON ENGINE COMPRISING ONE OR MORE CLOSED CYCLES Filed Aug. 13, 1948 or {/11 m9 #4 119 m a: m we 1/0 m 15,

ALEYANDRE HOROWITZ CORNELIS HERMAN BUlTENHUlS INVENTORS BY eawwm Patented Aug. 14, 1951 L 1 HOT-GAS PISTON ENGINE COMPRISING om:

on MORE CLOSED CYCLES.

Alexandre Horowitz and Cornelis Herman Buitenhuis, Eindhoven, Netherlands, assignors to Hartford National Bank and Trust Company, Hartford, Conn as trustee Application August 13, 1948, Serial No. 44,146 In the Netherlands September 13, 1947 4 Claims. (01. 60-24) This invention relates to engines comprising four cylinders and pistons movable therein, which cylinders are provided on two centre lines, .enclosing an angle of 90, so as to be grouped about the shaft of the engine, the pistons which are movable in the cylinders provided on the same centre line being rigidly coupled together, and the movements of the pistons being determined by a body which is rotatable about an eccentric seated on the shaft of the engine, said body exhibiting a sectional area which is substantially rectangular in a plane normal to the shaft of the engine. ,7

According to the invention, such an engine is constructed as a hot-gas pistonengine comprising closed cycles, each of the cycles being performed in two cylinders provided on different centre lines, the cylinders which are provided on the same centre line comprising solely cold spaces or solely hot spaces, and the heater, regenerator and cooler associated with a determined cycle jointly surrounding either of the two cylinders associated with the cycle concerned.

The term hot-gas piston engines is understood in this case to mean more particularly a hot-gas engine or a refrigerator operating on the reversed hot-gas piston principle.

The engine according to the invention exhibits the advantage that it permits of being constructed in a very compact manner, since transmission members, such as piston rods, driving rods and the like are dispensed with. From this ensues the important advantage, that the cold .and hot pistons associated with a cycle may be arranged to be very close to one another, so that the length of the communication channel between the cylinders in which the'pistons move and, consequently, the clearance space may be small, which greatly influences the specific power .of the engine. In general, a compact COIlStIllC-r tion of a hot-gas piston engine can be realised only with difficulty. From the thermal point of view, it is inconvenient if the cold space is liable to be exposed to the influence,.even small, of the hot parts of the engine. It is then often compulsory, in order to minimise this influence, to find a compromise by which the communication ducts between the hot and cold spaces and, hence, the clearance space become larger than is required or desired. In the engine according to the invention it is possible greatly to reduce-the .influence exerted by the heat of the hot parts upon the cold space, whilst nevertheless the clearance space remainssmall.

Inone embodiment of the invention,- the 'cylinderscomprising a cold space have a dimension, as measured in the direction of the centre line, which is smaller than that of the cylinders comprising a hot space, the star shape of the engine then changing to a rectangular shape. This rectangle has two long and two short sides and here one of the advantages of the invention, viz. the concentrated, compact structure of the engine, becomes greatly manifest. Furthermore the communication ducts are very short, since the cold spaces are located adjacent the coolers.

In a further embodiment of the invention, the engine is preferably constructed to be such that the ratio between the stroke of a piston and the diameter of the cylinder in which the piston moves is comprised between 0.3 and 0.4. Owing to this comparatively small ratio, as a result of which the stroke is small with respect to the diameter of the cylinder. important advantages are obtained, viz. the engine is even more compact in construction, occupies an even smaller space than the body eccentrically arranged on the main shaft already permitted and, in addition, the engine is capable of being dismounted in a simple and rapid manner.

The invention will now be described more fully with reference to the accompanying drawing, the figures of which are to be regarded as embodiments thereof, given by way of example.

Fig. 1 shows diagrammatically a hot-gas piston engine according to the invention.

Fig. 2 is a sectional view taken on the line II-II of the engine shown in Fig. 1.

Referring to Figs. 1 and 2, reference numeral IOI designates an engine housing, with which two cylindrical bodies I02 and I03 are joined.

These cylindrical bodies contain two other cylindrical bodies I04 and I05 so as to form between them an annular channel comprising the heattransfer elements of heatersl06 and I01 and of coolers I08 and I09. Elements I34 close off one end of the annular channels in'known manner. Regenerators H0 and III are provided between the two heaters and coolers. In the cylinders I04 and I05 can move two piston-shaped bodies IIZ'and II3, which are connected by coupling bodies H4 and H5. At right angles to the centre line of the cylinders I04 and I05 are two further cylinders H6 and H1 in which piston-shaped bodies H8 and H9 are moyable. The two piston-shaped bodies H8 and H9 are interconnected by coupling bodies I20 and lil, so that these pistons also perform, to a certain extent, a constrained movement. The spaces above the .pistons H8 and II! communicate through ducts I22 and I23 with the spaces above the pistons H3 and H2. The volume of one of the cycles provided is thus determined by the surfaces of the hot piston H3 and the cold piston H8 and the volume of the other cycle is accordingly determined by the surfaces of the hot piston H2 and the cold piston H9, Since the two piston surfaces determining the volume ofthe cycle exhibit a phase difference of 90, the cold piston then having the lead in the sense of rotation shown, the engine will operate as a faces I24, I25, I2 I and he c r espond n sides or therectangula hody I tha only rolling friction can occur between the corresponding surfaces. The ratio betweenthe stroke of the pis on and h di m e of th cy nd rs in which thepistons move, is 0.35 so that the pistons and h c th b d 0 n ed only-ne form comparatively small motions, whilst the en ine n v rtheless capable o d ve pin a compara iv ly hi h p we The hot-gas en n described, which s a xample of the inven i n, may b r ompa in con truct on, so tha an en in of a .ei t m n :DOwer will, as a rule, ccupy a sma ler s aeethan other similar-engines. Moreover, the mechanical losses e reduced o a min murnf a urther bearing with rollin frioti nis p ov ded be w en the rectangular body 1-39 and h eccent c 129, which is possible without the need for fur he means, "thereis onlyro ine-fri tionin he n ne With the excepti n f th fricti n o the piston rings lee-a ainst the Wa l o th c l nder, which i in t e en ines c o d to the in e on, enerally smaller than with the use o d iv ng rods. From a thermal viewpoint itis particularly adva t ous tha the coolers surround the hot cylinders and that the cold pistons are com.- parat-ively far remote from the hot part of the engine, whilst nevertheless the communication ducts i212 and I23 are as short as possible, so that the inevitable clearance space is very small. The housing of the enginecan also remain cool without the need forfurther means. Dismount ing of the engine concerned for inspection or the like may :be simple. After removal 'of a lid I3I, the 'bolts I32 connecting at one side the C011:- nectingpieces I I l and H5-to the piston VH2 m be loosened, whereupon after removal of lids n the cylinders lllland I33 the .two pistons I I2 and -I I3 may be takeniout of the engine. The pistons II 8 and I19, may beremoved in a similar manner. Since the gas pressures are invariably directed towards the .centre of the engine, the connecting pieces I26, LEI, III; and H5 are-invariably subject to pressure, :Since the connecting pieces are slightly resilient, troublesome play is prevented even-after some wear :and tear of the pressure surfaces.

What we claim is:

1- .A h p s n en ine c mp isin fou cyli d e v n a mo abl pisto th e n, a drive shaft for said engine, said cylinders being arran d ar u dsa d rive sha in two pa r one of said two pairs being arran edon acenter line which ;.i.ntersectssubstantially perpendicularly with the center line of the other pair, both of said center lines in turn intersecting the center line of said shaft substantially perpendicularly thereto, said cylinders of each of said pairs being located on-opposite sides of said shaft, respectively, said pistons in said cylinders which are opposite each other on the same center line being rigidly coupled to one another, an eccentric mounted on said shaft, a body surrounding said eccentric, said eccentric being rotatable in said body, said body having a sectional area which is sub tantial tan ar in a p a normal to said shaft, said pistons comprising means for imparting their movement to said body, both cylinders of one of said pairs each comprising a separate hot space, both cylinders .of the other'of said pairs each comprising a separate cold space, conduit means communicating one cylinder of one of said pairs with one cylinder of the other of said pairs, and a heater, regenerator and cooler operativel-y associated with each communicating pair of cylinders.

2. A hot-gas piston engine comprising fou-r cylinders each having a movable piston therein, a drive shaft for said engine, said cylinders being arranged around said drive shaft in two pairs, one of .said two pairs being arranged on a center line which intersects substantially perpendicularly with the center line of the other pair, both of said center lines in turn intersecting the center line of said shaft substantially perpendicularly thereto, said cylinders of each of said pairs being located on opposite sides of said shaft, respectively, said pistons in said cylinders which are opposite each other on the same center line being rigidly coupled toone another, an eccentric mounted on said shaft, a body surrounding said eccentric, said eccentric being rotatable in said body, said body having a sectional area which is substantially rectangular in a plane normal to said shaft, said pistons cornprlsing means for imparting their movement to said body, "both cylinders of one of said pairs thereof each comprising a separate hot space, both cylinders of the other of said pairs each comprising a separate cold space, said pair of cylinders which comprise said separate hot spaces having a dimension, as measured in the direction of the center line thereof, which is larger than that of said pair of cylinders which comprise said separate cold spaces, conduit means communicating one cylinder of one of said pairs with one cylinder of the other of said pairs, and a heater,-regenerator and cooler operatively associated with each communicating pair of cylinders.

3. A hot-gas piston engine comprising four cylinders each having a predetermined diameter and each-having a-movable piston therein, a drive shaft for said engine, said cylinders being arranged around said drive shaft in two pairs, one of said two pairs being arranged on a center line which intersects substantially perpendicularly with :the center line of the other pair, both of said center lines in turn intersecting the center line of said shaft substantially perpendicularly thereto,said.cylinders of each ,of said pairs being located on .oppositesides of said shaft, respective..- ly,..said'pistons in sai cylinders which areo po, site .eachvother on the same center line being rigidly coupled to one another, an eccentric mounted on said shaft, a body surrounding said ecc nt ic. said eeoentri bein tatable in said y, said y havin a sec i nal area which is s bst ntially rectangula i a plane n rmal to said shaft, said pistons comprising means for imparting their movement to said body, the ratio between the stroke of each of said pistons and of the diameter of the said cylinder in which the associated one of said pistons moves, being between 0.3 and 0.4, both cylinders of one of said pairs thereof each comprising a separate hot space, both cylinders of the other of said pairs each comprising a separate cold space, conduit means communicating one cylinder of one of said pairs with one cylinder of the other of said pairs, and a heater, regenerator and cooler operatively associated with each communicating pair of cylinders.

4. A hot-gas piston engine comprising four cylinders each having a predetermined diameter and each having a movable piston therein, a drive shaft for said engine, said cylinders being arranged around said drive shaft in two pairs,

one of said two pairs being arranged on a center line which intersects substantially perpendicularly with the center line of the other pair, both of said center lines in turn intersecting the center line of said shaft substantially perpendicularly thereto, said cylinders of each of said pairs being located on opposite sides of said shaft, respectively, said pistons in said cylinders which are opposite each other on the same center line being 6 rigidly coupled to one another, an eccentric mounted on said shaft, a body surrounding said eccentric, said eccentric being rotatable in said body, said body having a sectional area which is substantially rectangular in a plane normal to said shaft, said pistons comprising means for imparting their movement to said body, the ratio between the stroke of each of said pistons and of the diameter of the said cylinder in which the associated one of said pistons moves, being between 0.3 and 0.4, both cylinders of one of said pairs thereof each comprising a separate hot space, both cylinders of the other of said pairs each comprising a separate cold space, said pair of cylinders which comprise said separate hot spaces having a dimension, as measured in the direction of the center line thereof, which is larger than that of said pair of cylinders which comprise said separate cold spaces, conduit means communicating one cylinder of one of said pairs with one cylinder of the other of said pairs, and a heater, regenerator and cooler operatively associated with each communicating pair of cylinders.

ALEXANDRE' HOROWITZ. CORNELIS HERMAN BUITENHUIS.

No references cited. 

